Innistrad: Crimson Vow/Trivia

Maro's Crimson Vow teaser

Mark Rosewater gave his traditional teaser with the following hints.^[1]

The following counter types:
- Bloodline —
- Croak — Grolnok, the Omnivore
- Invitation —
- Judgment —
- Omen —
- Slime —
- Suspect —
A new mechanic that removes something never removed before — Cleave (rules text)
A popular and powerful creature card from an Innistrad set gets reprinted — Thalia, Guardian of Thraben
A new artifact token, along the lines of Clue, Food and Treasure — Blood
A card that makes red Dragon Illusion creature tokens with flying and haste —
A mechanic that first appeared as a faction mechanic returns — Exploit
A new legendary creature card that combines two characters that previously each had their own legendary creature card —
A new card that lets you cast certain cards off the top of your library —
A new mechanic which is a mirror of an already existing mechanic —
A legendary character returns, but now as a Vampire —

“Choose a number between 0 and 13.” — By Invitation Only
“with mana value less than or equal to the number of Vampires you control” —
“If it’s red, you may cast it this turn.” —
“Zombies you control have flying.” —
“At the beginning of your upkeep, any opponent may sacrifice a creature.” —
“Kraken, Leviathan, Octopus, or Serpent” —
“twice that many of those tokens are created instead.” —
“Whenever a Human you control dies,” —
“equal to the number of permanents you control that are Spirits and/or enchantments.” —
“Then if you control exactly thirteen permanents,” —